12698944

1. [
2. {
3. "step": 1,
4. "title": "High-Pressure System Residual Pressure Depressurization",
5. "instruction": "Pull the fuel pump module fuse in the engine bay underhood junction block. Crank engine for 5 seconds until it stalls, then disconnect the negative battery terminal."
6. },
7. {
8. "step": 2,
9. "title": "Intake Manifold & Sound Insulator Removal",
10. "instruction": "Unclip wiring harness retainers, disconnect PCV breather tubes, and remove upper acoustic foam insulator and intake manifold assembly to expose the valley-mounted HPFP."
11. },
12. {
13. "step": 3,
14. "title": "Rigid High-Pressure Fuel Feed Pipe Removal",
15. "instruction": "Use a backup flare nut wrench on the pump fitting while loosening the high-pressure fuel pipe nut. Always discard single-use high-pressure metal pipes per GM service specifications."
16. },
17. {
18. "step": 4,
19. "title": "Pump Removal & Roller Lifter Tappet Inspection",
20. "instruction": "Evenly loosen the two mounting bolts in half-turn increments to prevent plunger cocking. Extract the pump and inspect the internal roller tappet and camshaft lobe for scuffing, pitting, or flat spots."
21. },
22. {
23. "step": 5,
24. "title": "New Pump Installation & Torque Sequence",
25. "instruction": "Lubricate the new Viton O-ring and roller tappet with clean engine oil. Rotate engine until cam lobe is at base circle. Torque mounting bolts evenly to 15 N·m (133 in-lb) and fuel pipe union nut to 30 N·m (22 lb-ft)."
26. }
27. ]

Common diagnostic trouble codes (DTCs) triggered when this common rail injector experiences wear, circuit faults, or calibration drift: